package 树;
/**
 * https://leetcode-cn.com/problems/populating-next-right-pointers-in-each-node/
 */
public class _116_填充每个节点的下一个右侧节点指针 {
    class Node {
        public int val;
        public Node left;
        public Node right;
        public Node next;

        public Node() {}

        public Node(int _val) {
            val = _val;
        }

        public Node(int _val, Node _left, Node _right, Node _next) {
            val = _val;
            left = _left;
            right = _right;
            next = _next;
        }
    };

    //连接root节点的左右子节点
    public Node connect(Node root) {
        if(root == null) return null;
        connectTwoNode(root.left,root.right);

        return root;
    }

    //函数定义：连接node1和node2节点
    private void connectTwoNode(Node node1,Node node2){
        if(node1 == null || node2 == null) return;

        //连接两个相邻的节点
        node1.next = node2;

        connectTwoNode(node1.left,node1.right);
        connectTwoNode(node2.left,node2.right);
        connectTwoNode(node1.right,node2.left);

    }
}
